Top

Narwhal

February 8, 2011 by · Comments Off on Narwhal 

Narwhal, The narwhal, Monodon Monoceros is a medium sized toothed whale that lives all year in the Arctic. One of two species of whales that live in the family Monodontidae and beluga, narwhal males are distinguished by a characteristic long, straight, extending their defense helical left upper jaw. Mainly found in the Canadian Arctic and Greenland waters rarely south of latitude 65 ° north, the narwhal is a unique specialized predator in the Arctic. In winter it feeds on benthic prey, mainly fish dishes, at depths up to 1500 m thick under the ice. Narwhal were collected for over a thousand years by the Inuit of northern Canada and Greenland for meat and ivory and regulated subsistence hunting continues to this day. Although populations appear stable, the narwhal was considered particularly vulnerable to climate change due to a narrow range of geographic and specialty food.

Male narwhals weigh up to 1,600 kilograms (3,500 pounds) and females weigh about 1,000 kilograms (2,200 pounds). The pigmentation of the narwhal is a mottled black and white pattern. They are darker at birth and become whiter in color with age.

The most outstanding characteristic of male narwhal is its only 2-3 meters (7-10 m) long defense. It is an incisor that projects from the left side of the upper jaw and forms a left propeller. The defense may be up to 3 meters (9.8 feet) long with respect to a body length of 4-5 meters (13-16 feet) and weigh up to 10 kg (22 lb). About one in 500 men with two tusks, which occurs when the right incisor, normally small, also grows. A female narwhal is shorter and straight defense. It can also produce a second defense, but this happens rarely, and there is only one recorded case of a female with dual tusks.

The most accepted theory for the role of defense is a secondary sexual characteristic, like a lion’s mane or tail feathers of a peacock. This particular hypothesis has been discussed at length and defended by Charles Darwin in The Descent of Man and Selection in Relation to Sex (1871). It can help determine the social rank, to maintain or hierarchies of domination helps boys develop the skills necessary to carry into adult gender roles. Narwhals have rarely been observed using their tusks to fight against, other aggressive behavior or to break the sea ice in their arctic habitat.

Narwhals have a diet relatively small and specialized. Their prey is mainly composed of Greenland halibut, polar cod and Arctic, shrimp and squid Gonatus. Additional items found in stomachs included wolves, capelin, skate eggs and sometimes rocks, accidentally swallowed when whales feed near the bottom.

Narwhals have seasonal migrations with great fidelity to return to the ice-free preferred summering grounds, usually in shallow waters. In winter they are found primarily in the offshore, deeper waters under thick sea ice, crack emerged in the narrow sea ice, or conduit. Narwhals from Canada and western Greenland ice winter regularly in the Davis Strait and Baffin Bay along the continental slope with less than 5% free water and high densities of Greenland halibut. Feeding in winter accounts for a greater portion of energy intake narwhal in the summer and, as marine predators, they are unique in their successful exploitation of Arctic ecosystems in deep water.

Some medieval Europeans believed narwhal tusks to be the horns from the legendary unicorn. Because these horns were considered to have magical powers like the ability to cure poison and melancholy, the Vikings and other northern traders were able to sell for several times their weight in gold. The tusks were used to make cups that were thought to negate any poison that may have slipped into the drink. During the 16th century, Queen Elizabeth received a narwhal tusk carved and inlaid with gems for £ 10 000, the cost of a castle (about £ 1.5 to 2.5 million in 2007, using the index of retail prices). The tusks were staples of the cabinet of curiosities.
In Inuit legend, tusk was created when a woman with a rope attached to the spear around his waist has been dragged into the sea after the spear had hit a large narwhal. It was turned into a narwhal itself, and her hair, she wore a twisted knot, became defense spiral feature narwhal. [via wikipedia and various online sources]

Bottom